Dear Statalist,

I have a dataset with European and non-European countries. I define "europe" as:
Code:
gen europe=1 if Countrycode=="AT"|Countrycode=="BG"|Countrycode=="CH"
replace europe=0 if europe==.
and "non-europe" as
Code:
gen noneurope=1 if Countrycode=="AU"|Countrycode=="BR"|Countrycode=="CN"
replace noneurope=0 if noneurope==.
The definition here europe and non-europe are mutually exclusive, there is no overlap or a third category.

Then I generate an investment score, "score", which is the aggregate score of all investors in the same country:
Code:
bysort id year :egen score_europe = total(score) if europe==1
bysort id year :egen score_noneurope = total(score) if noneurope==1
and I want to regress both score_europe and score_noneurope in the same regression with AEM as the DV and some control variables:
Code:
reg AEM score_europe score_noneurope ROA MB growth leverage i.industry i.year i.country_id ,cl(id)
And Stata tells me there is no observation. I kind of understand why there is no observation as the two IVs have no overlap. But if I want to regress score_europe score_noneurope in the same regression, what should I do to achieve this?

Thanks!